Coined end panel

ABSTRACT

The distortion resistance of a non-detachable end closure is increased by coining of the area surrounding the opening flat well. Non-detachable end closures wherein the opening flap is located at the base of a wall formed in the end panel may evidence distortion or &#39;&#39;&#39;&#39;blow out&#39;&#39;&#39;&#39; of the well structure due to internal overpressurization. Coining of the area surrounding the well increases the distortion resistance of the well structure.

United States Patent 1 [111 3,912,113

Peyser et al. [4 1 0a. 14, 1975 COINED END PANEL [75] Inventors: Harry A. Peyser, Olympia Fields; Primary Examiner William Price Assistant Examiner-Steven M. Pollard d H t P both f h 5 Ward J erbs Osen O Attorney, Agent, or Fzrm.lohn J. Kowalik', Joseph E.

Kerwin; William A. Dittmann [73] Assignee: Continental Can Company, Inc.,

New York, N.Y.

[22] Filed: Nov. 8, 1974 [21] Appl. No.: 521,996

[57] ABSTRACT The distortion resistance of a non-detachable end closure is increased by coining of the area surrounding the opening flat well. Non-detachable end closures [52'] U.S. Cl 220/268; 220/269 h r n h i ening l p is located at the base of a [51] Int. Cl. B65D 41/32 Wall f rm n the end panel may evidence distortion [58] Field of Search 220/265, 266, 268, 281, Or blow out Of the well structure due to internal 220/260, 90.6; 229/7 R; 222/541 'overpressurization. Coining of the area surrounding the well increases the distortion resistance of the well [56] References Cited tructure.

UNITED STATES PATENTS 7 Claims 4 Drawing Figures 3,757,989 9/1973 Brown 220/269 l0 Y! T US. Patent ()Ct. 14, 1975 3,912,113

COINED END PANEL SUMMARY OF THE INVENTION Non-detachable end closures, of the type wherein the opening flap is located at the base of a well formed in the end panel may evidence distortion or blow out of the well structure due to internal overpressurization. Typical conventional end closures can tolerate internal pressures of 80-85 p.s.i. without distortion.

Coining of the area surrounding the well has been found to increase the pressure tolerance to 95-100 p.s.i.

It is, therefore, an important object of the present invention to provide a non-detachable end closure with increased distortion resistance.

It is a further object to provide a non-detachable end closure with increased pressure tolerance.

DESCRIPTION OF THE DRAWINGS The various features and advantages of the improved non-detachable end closure of this invention will be more apparent from the following detailed description when considered in connection with the accompanying drawing wherein:

FIG. 1 is a top view of the improved end closure of this invention; and

FIG. 2 is a sectional view of the improved end closure of this invention taken through the center of the opening flap, illustrating the location of the coined area; and

FIG. 3 is an enlarged fragmentary sectional view of the well wall and surrounding area, illustrating the coin configuration; and

FIG. is an enlarged fragmentary sectional view of the well wall and surrounding area of an uncoined end closure.

DESCRIPTION OF THE PREFERRED EMBODIMENT There is illustrated a non-detachable end closure generally designated 1 having a chuck wall 2 joined to an end panel 3 by a ledge 4. The end closure 1 is formed with a circular or cylindrical well 5 in an area between the end panel center and the chuck wall 2, said well 5 having at its base a crush score 6 partially encircling an opening flap 7. The uncrushed area provides a hinge portion (not shown) which connects the flap 7 with the end panel 3 when the flap 7 is torn away from the end panel 3 and pushed into the container. The periphery of the well 5 is strengthened by coining, thereby increasing the pressure tolerance of the end closure by approximately 15 p.s.i. The circular coin area 9, which results in a thickness reduction of approximately 0.002 inches, extends beyond the top radius 13 of the uncoined well wall 8 to the point of tangency ll of the uncoined radius 13 with the center panel 3. The effect of the coining is to reduce the bend radii 12 at both ends of the well wall 8, as well as the top radius 13, thereby bringing the wall 8 into a position more nearly perpendicular to both the end panel 3 and the opening flap 7. This results in the stress on the wall 8 being taken in substantially pure compression while the shear component is essentially eliminated. Since the well wall 8 is stronger in compression than in shear, this modification of the stress load increases the buckling resistance of the well structure.

We claim:

1. In a non-detachable end closure for a container, comprising an end panel including a ledge, said end panel being formed with a well having a wall in an area between the center of the end panel and said ledge, said well having at its base a partial score and an opening flap partially encircled thereby:

the improvement comprising a distortion-inhibiting coined area in the panel encompassing said well.

2. The invention as described in claim 1, wherein said well wall and said end panel merge in a top radius and said coined area extends beyond said top radius to the point of tangency with said end panel.

3. The invention described in claim 1 wherein said well is cylindrical.

4. The invention described in claim 1, wherein said coined area is depressed below the external surface of said end panel.

5. The invention described in claim 4, wherein said coined area is circular and said well wall and said end panel merge in a top radius and said coined area extends beyond said top radius to the point of tengency with said end panel.

6. The invention described in claim 5, wherein the thickness of said well wall exceeds the thickness of said coined area of said end panel.

7. The invention described in claim 6, wherein said well wall is substantially perpendicular to both said end panel and said base of said well. 

1. In a non-detachable end closUre for a container, comprising an end panel including a ledge, said end panel being formed with a well having a wall in an area between the center of the end panel and said ledge, said well having at its base a partial score and an opening flap partially encircled thereby: the improvement comprising a distortion-inhibiting coined area in the panel encompassing said well.
 2. The invention as described in claim 1, wherein said well wall and said end panel merge in a top radius and said coined area extends beyond said top radius to the point of tangency with said end panel.
 3. The invention described in claim 1 wherein said well is cylindrical.
 4. The invention described in claim 1, wherein said coined area is depressed below the external surface of said end panel.
 5. The invention described in claim 4, wherein said coined area is circular and said well wall and said end panel merge in a top radius and said coined area extends beyond said top radius to the point of tengency with said end panel.
 6. The invention described in claim 5, wherein the thickness of said well wall exceeds the thickness of said coined area of said end panel.
 7. The invention described in claim 6, wherein said well wall is substantially perpendicular to both said end panel and said base of said well. 